The present application is related to, and claims priority from, Japanese Patent Application No. 2002-300677 filed on Oct. 15, 2002. The entire contents of the application is hereby incorporated by reference in its entirety.
1. Field of the Invention
This invention relates to a cantilever type probe card and a method for the production thereof.
2. Description of the Related Art
A probe card is used for the purpose of measuring on a semiconductor wafer the performance of a device (an object under test) which is formed on the semiconductor wafer. The probe card is provided with a plurality of probe needles intended to contact a pad of the device. To test a given device for performance, the probe card is attached to a measuring apparatus called an xe2x80x9cautoproberxe2x80x9d and the probe needles illuminated with a lightening fixture are photographed with a camera designed exclusively for this purpose. The positions of the tips of the probe needles are perceived on the basis of the image so photographed and the position of the device is adjusted in conformity with the perceived positions.
Incidentally, since the semiconductor devices developed in recent years have been densified to a great degree, pads formed individually for the devices have become proportionately small and the intervals between the pads have become thin accordingly as well. As a result, the probe needles which are formed in the probe card have come to be disposed in high density with narrow intervals. The narrowing of the intervals between the probe needles renders the perception of accurate positions of the tips of the probe needles difficult. This is because the probe needles cause the light of illumination to be so irregularly reflected that the positions of the tips of the probe needles may not be accurately perceived from the photographed image.
As a means for solving the problem of this irregular reflection, the official gazette of JP-A-2002-40052 (Cited Reference 1) discloses a technique which, concerning a membrane type probe card having probe needles laid out in high density, consists in applying a black coat to the probe needles excepting the contact points of the probe needles that are fated to contact the pads of devices. The term xe2x80x9cmembrane type probe cardxe2x80x9d used herein means such a probe card which is obtained by forming on a film such printed wirings as are eventually formed on a wiring board and polishing the leading terminal parts of the printed wirings thereby forming contact points.
A probe card which has a plurality of needles of tungsten arranged on the main body thereof is referred to as a xe2x80x9ccantilever type probe card.xe2x80x9d With the object of preventing this cantilever type probe card from entailing the problem of inferior insulation between the adjacent probe needles which are arranged in high density unlike the aforementioned problem of irregular reflection, the official gazette of JUMR-A-3038114 (Cited Reference 2) discloses a probe card which imparts enhanced insulation between the adjacent probe needles by coating all the probe needles individually with an insulating film by means of electrodeposition coating.
When the technique of the membrane type probe card according to the Cited Reference 1 mentioned above is to be applied to the cantilever type probe card, the probe needles are fated to be wholly coated in black, namely they are individually coated as proposed in the Cited Reference 2 mentioned above. Thus, the cantilever type probe card incorporating this technique has the problem of rendering the production thereof extremely difficult.
It is, therefore, an object of this invention to provide a cantilever type probe card which is capable of easily perceiving the positions of the tips of the probe needles.
Another object of this invention is to provide a method for the production of a cantilever type probe card which is capable of facilitating perception of the positions of the tips of the probe needles.
This invention relates to a cantilever type probe card, i.e. a probe card having disposed at prescribed positions of the main body thereof such probe needles as are each furnished at the leading terminal thereof with a bent part directed toward an object under test, wherein at least the portions of the probe needles which include the bent parts mentioned above have each formed therein a reflection-lowered part, namely a part processed to repress the reflection of light. The reflection-lowered parts mentioned above are preferred to be given a lusterless coating. Preferably these reflection-lowered parts are delustered by the treatment of brushing.
The probe card of this invention is furnished at prescribed positions of the main body thereof with probe needles each forming at the leading terminal thereof a bent part directed toward an object under test and antireflection plates covering the bent parts of the probe needles.
This invention relates to a method for the production of a cantilever type probe card, i.e. a method for producing a probe card having disposed at prescribed positions of the main body thereof such probe needles as are each provided at the leading terminal thereof with a bent part directed toward an object under test, wherein the bent parts of the probe needles mentioned above are endowed with a delustering coat by immersing at least the bent parts in a coating material while horizontally retaining the probe card in a state having the probe needles disposed at the prescribed position.
The method of this invention is directed toward the production of a probe card, i.e. a probe card having disposed at prescribed positions of the main body thereof such probe needles as are each forming a bent part directed toward an object under test, wherein at least the bent parts of the probe needles mentioned above are delustered by being brushed with a metallic brush till the probe needles sustain fine scratches.
Further, the method of this invention is directed toward the production of a probe card, i.e. a probe card having disposed at prescribed positions of the main body thereof such probe needles as are each forming a bend part directed toward an object under test, wherein antireflection plates adapted to cover the bent parts of the probe needles and provided with openings for exposing the tips of the probe needles are attached by adhesion to the main body of the probe card.